A United Airlines plane flying to Hawaii was forced to make an emergency landing after its engine began to fall apart mid-air.

After what was described as “the scariest flight of my life” by one passenger, photos and videos taken through the windows showed an exposed engine shaking in mid-air after the “engine cowling” broke away.

The drama on board the Boeing 777-222 began after a loud bang was heard roughly 35 minutes before the flight was scheduled to land in Honolulu. The pilots immediately sent out a distress call and were forced to make an emergency landing.

A Google engineer on board the flight, Erik Haddad, who had a clear view of the exposed engine, apparently remained calm throughout the incident, uploading a series of photos to Twitter and quipping: “I don’t see anything about this in the manual.”

Another passenger, Maria Falaschi, who uploaded a series of dramatic photos, said it was the “scariest flight of my life” but the pilots did “a great job and so did the crew”, adding that the passengers were prepared for an emergency landing by crew who “handled it well”.

A statement from United Airlines said the flight landed safely at 12.38pm local time. “United flight 1175 traveling to Honolulu from San Francisco landed safely after the pilots called for an emergency landing because of an issue with the #2 engine. Our pilots followed all necessary protocols to safely land the aircraft.

Aircraft rescue and firefighters met the plane on the tarmac, United said. “The aircraft taxied to the gate and passengers deplaned normally. United is fully cooperating with the NTSB and FAA investigation of the event.”

United said it was “fully cooperating” with investigations by the Federal Aviation Administration and the National Transportation Safety Board.